13121404421 has 4 divisors (see below), whose sum is σ = 13163595744. Its totient is φ = 13079213100.

The previous prime is 13121404397. The next prime is 13121404447. The reversal of 13121404421 is 12440412131.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 13121404421 - 2⁶ = 13121404357 is a prime.

It is a super-5 number, since 5×13121404421⁵ (a number of 52 digits) contains 55555 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13121304421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21095195 + ... + 21095816.

It is an arithmetic number, because the mean of its divisors is an integer number (3290898936).

Almost surely, 2^13121404421 is an apocalyptic number.

It is an amenable number.

13121404421 is a deficient number, since it is larger than the sum of its proper divisors (42191323).

13121404421 is an equidigital number, since it uses as much as digits as its factorization.

13121404421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42191322.

The product of its (nonzero) digits is 768, while the sum is 23.

Adding to 13121404421 its reverse (12440412131), we get a palindrome (25561816552).

The spelling of 13121404421 in words is "thirteen billion, one hundred twenty-one million, four hundred four thousand, four hundred twenty-one".